教学课程资源库 更多>>

关键词： 悉生生物学   无菌动物   正常微生物群   内环境   生态因素   悉生动物   外环境   生态关系   生态规律   微生态学  

摘要： 人类的生存和繁衍必须适应环境,一个是外环境,即宏观生态;另一个是内环境,即微观生态。宏观生态人们对之已有一定的认识;土壤、空气和水的污染对人类的影响显而易见,因此人们比较重视。正常微生物群与其宿主——人和动物所构成的内环境的微观生态,却因看不见、摸不着而常忽视。其实,微观生态关系的重要性不亚于宏观生态,一切宏观生态因素都必然要通过微观生态规律而起作用。

摘要： The reproductive biology of the black mastiff bat has been examined using animals maintained in a laboratory colony. Ovulation was found to be spontaneous and occurred only from the right ovary. The corpora lutea appeared to be functional, and decidual reactions developed in the uterus during the luteal phase of the cycle even in the absence of an implanting blastocyst. At the end of nonpregnant, ovulatory cycles much of the endometrium became necrotic and was desquamated with associated bleeding. In the event of pregnancy only a single blastocyst implanted in the right uterine horn, and the discoidal chorioallantoic placenta then developed at the cranial end of that horn. This was preceded by the development of an unusual vascular tuft in the endometrium in that region. The endothelial cells of the tuft vessels became hypertrophied during early pregnancy and developed more prominent basal laminae. Trophoblast then grew preferentially around these vessels. These observations suggest that factors secreted by endometrial endothelial cells and incorporated at least in part into their basal laminae may play a central role in controlling early trophoblastic growth during the morphogenesis of the discoidal chorioallantoic placenta in this bat. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company

摘要： Reviews the book 'The Biology of Large African Mammals in Their Environment,' edited by P.A. Jewell and G.M.O. Maloiy.

关键词： Phryganella acropodia   Testate amoeba   Growth rate   Rhizopoda   Feeding   Fungal species   Ultrastructure  

摘要： Clones of Phyrganella acropodia were cultivated under different trophic conditions with bacteria as the food source. The doubling time was estimated to be 3 days. The edibility of four species of fungi, Aspergillus niger, Cunninghamella echinulata, Penicillium echinulatum and Stilbella bulbicola, was tested, but only Penicillium enchinulatum and Stilbella bulbicola were eaten and digested by the amoeba. An ultrastructure examination showed that there are two contractile vacuoles, many dictyosomes, a single nucleus with several nucleoli, and peroxisomes. The pseudopodia are filiform when attached to the substrate but change to lobose when the animal is floating. A thin organic membrane covers the aperture of resting forms.

关键词： 缺硒病   发病机理   硒缺乏症   病原诊断   动物营养   流行病学调查   雏禽   玉米籽实   玉米植株   低硒环境  

摘要： 本课题根据实验病理学原则和分组对比的方法,通过用低硒基础日粮分别加硒(0.2ppm)与不加硒,对仔猪、雏禽进行饲喂,取得了畜禽硒缺乏症病例复制的成功。综合实验研究结果,明确了疾病的基本临床—病理特征,澄清了种属间的异同,阐明了发病机理并绘制了示意图,取得了理论研究的重要成果。研究工作结合黑龙江省实际,从全省范围对畜禽硒缺乏症做了系统的流行病学调查并在代表性地区采集了土壤、饲料和畜禽血液样本,分析测定了硒含量。总结了疾病的流行病学特征,明确了病区。调查、测定结果证实病区与低硒环境密切相关。根据研究资料绘制了全省的病区与环境硒分布图,填补了空白。在该病的诊断与防治方面,明确了综合确诊根据、提出了病原诊断标准并发现家禽羽硒与血硒和组织硒含量呈良好的正相关。鉴于羽毛有采取、保存、递送方便和检测值准确、稳定等优点,羽硒含量不仅可做为病原诊断的亚临床指标,更可用以监测禽群的硒营养状况和评定环境硒水平,有着重要的实际意义。玉米植株叶面喷硒试验结果表明,可明显提高玉米籽实含硒量,使之基本达到动物营养需要水平。为从根本上预防硒缺乏症,找到了一种有效、可行的新方法。建议在广大低硒地带推广、应用。

关键词： 动物微生物学   实验动物   品质标准   鼠痘   网络系统   生命科学   鸡败血霉形体   肺霉形体   败血性   生物安全  

摘要： 实验动物在生命科学研究领域中,已被公认是不可缺少的“活的精密仪器”。既然涉及精密,就必然要有一定的品质要求和标准,以保证在实验研究中具有良好的灵敏性、准确性和重复性。 1970年代以来,国际上有关实验动物学的机构,都已把实现“实试动物标准化”列为主要的工程项目之一。世界卫生组织(WHO)和国际实验动物学理事会(ICLAS)都已在世界各地发展、建立了实验动物品质监测咨询中心及网络系统,以推动实现国际上实验动物的标准化。实验动物微生物学品质的监控,是实现实验动物标准化的主要措施之一。

关键词： 胚泡   神经内分泌学   受体复合物   激素受体   作用机理   活性物质   反向调节   激素调控   生殖生物学   研究实验室  

摘要： 当前国际上在生殖生物学研究方面进展迅速。主要有下列若干方面:在激素调控和作用机理方面主要有 C—AMP 和 Ca 离子的调节机理;激素受体的分析和激素受体复合物的转运、储存、降解以及对基因表达调节的原理;激素的反向调节和激素内入的机制,生殖神经内分泌学研究等,在着床机理方面,近年已进入细胞和分子水平。集中探讨着床信息的活性物质。包括子宫和胚泡中肽类物质的分离与纯化,信使的物质基础。